Due to the limited number of suitable antenna locations it will be necessary in the future, with the introduction of new radio communication standards or new radio transmission methods, to combine a plurality of carrier signals from base stations conforming to different radio communication standards and radiate said signals via a common antenna arrangement.
With the method known as “broadband hybrid combining”, in the case of low power levels a plurality of carrier frequencies associated with different radio communication standards are combined, amplified and radiated. A highly linear, analog transmission power amplifier is used for the purposes of amplification, a predistortion method possibly being applied in addition for linearization purposes. Transmission power amplifiers of said kind are described in more detail in, for example, “RF Power Amplifiers for Wireless Communications”, by Steve C. Cripps, Artech House, Boston, 1999, though said amplifiers can be implemented only at very great cost owing to high technical requirements.